protected override long CalculateOutput()
{
// Sort the inputs into ascending order
_input.Sort();
// Add the starting input of 0
_input.Insert(0, 0);
// Add the final input of [largest input + 3]
_input.Add(_input[_input.Count - 1] + 3);
// For each number, map the subsequent numbers it can connect to
Dictionary <long, TernaryGraphNode> nodeMap = new Dictionary <long, TernaryGraphNode>();
TernaryGraphNode currentNode;
for (int i = _input.Count - 1; i >= 0; i--)
{
currentNode = new TernaryGraphNode();
for (int offset = 1; offset <= 3; offset++)
{
if (i + offset < _input.Count)
{
switch (_input[i + offset] - _input[i])
{
case 1:
nodeMap.TryGetValue(_input[i + offset], out currentNode.child1);
break;
case 2:
nodeMap.TryGetValue(_input[i + offset], out currentNode.child2);
break;
case 3:
nodeMap.TryGetValue(_input[i + offset], out currentNode.child3);
break;
}
}
}
nodeMap.Add(_input[i], currentNode);
}
Debug.LogFormat("Generated {0} ternary tree nodes", nodeMap.Count);
// Traverse the ternary tree, counting the number of possible paths
Dictionary <TernaryGraphNode, long> onwardPathCounts
= new Dictionary <TernaryGraphNode, long>();
onwardPathCounts.Add(nodeMap[_input[_input.Count - 1]], 1);
CountOnwardPaths(onwardPathCounts, nodeMap[0]);
for (int i = _input.Count - 1; i >= 0; i--)
{
Debug.LogFormat("Input {0} ({1}) has {2} onward path possibilities",
i, _input[i], onwardPathCounts[nodeMap[_input[i]]]);
}
return(onwardPathCounts[nodeMap[_input[0]]]);
}
private long CountOnwardPaths(Dictionary <TernaryGraphNode, long> onwardPathCounts,
TernaryGraphNode node)
{
if (!onwardPathCounts.ContainsKey(node))
{
long count = 0;
if (node.child1 != null)
{
count += CountOnwardPaths(onwardPathCounts, node.child1);
}
if (node.child2 != null)
{
count += CountOnwardPaths(onwardPathCounts, node.child2);
}
if (node.child3 != null)
{
count += CountOnwardPaths(onwardPathCounts, node.child3);
}
onwardPathCounts.Add(node, count);
}
return(onwardPathCounts[node]);
}
